If you want to visualize the entity in a Unity client, you would have to create a
Player entity as implemented in the Starter Project.

1. Create the prefab

Prefabs are the basic Unity asset type, which have a 1-1 relationship with the entity templates used
to create SpatialOS entities. The prefab name is referenced as part of the entity template, so it makes sense to create the prefab first.

This can be done in a multitude of ways, one of the simplest being:

Right-click in the Unity Hierarchy panel.

Either select Create Empty or one of the basic templates (for example, Cube).

Selecting this in the hierarchy then displays the prefab details in the Unity Inspector panel:

If you selected CreateEmpty, the prefab will only have the Unity Transform component in the
inspector and no physical or visual representation in the Unity Scene viewport.

At this point you could add other Unity MonoBehaviours to the prefab, such as a typical
TransformReceiver and TransformSender pair to handle position updates.

Spawn the prefab named Cube (which you previously created) at position (0, 0, 0)

Give the server write access over the position.

Allow the entity to be persisted to a snapshot.

Grant read access of the entity to both the server and clients.

3. Add the entity to a snapshot

Adding an entity to the snapshot means it will be present in the world when the simulation starts.
There is a template script to programmatically generate snapshots, SnapshotMenu.cs under
Assets/Editor, that is used in the tutorials and the Starter Project.